Gang lock arrangements for filing cabinets and the like, in which a plurality of drawers may be locked in a closed position by means of a single locking arrangement, have been used for many decades. For example, U.S. Pat. No. 2,829,021 discloses such an arrangement in which one of the drawers—a lock drawer—of a multi-drawer cabinet includes a plunger for moving a pair of locking rods such that all of the drawers are retained in their closed position. The lock drawer also includes a locking bolt and combination lock, to lock the plunger in place, thereby locking all of the drawers, including the lock drawer, in their closed position.
Additionally, U.S. Pat. No. 3,070,046 discloses a multi-drawer cabinet in which a locking unit includes a pair of lift bolts arranged to lift corresponding lock bars of a gang lock arrangement, to retain all of the drawers in their closed position. The locking unit includes a locking means with a combination lock, to lock the lift bolts in place, thereby locking the drawers in their closed position. The locking unit is described as a lock drawer, but it is held in place in the cabinet by means of metal screws.